Decorative laminate of thermoplastic material

ABSTRACT

A decorative laminate of thermoplastic material which is capable of obscuring surface imperfections in the surface to which it is applied comprises a base layer containing not more than 2% by weight of plasticizer and a decorative layer, the base layer being two to four times the thickness of the decorative layer and the laminate having a total thickness of between 250 and 450 microns and a shrinkage of less than 0.5% at ambient temperatures.

This invention relates to decorative laminates and particularly tolaminates comprising thermoplastic material.

Thin decorative sheet materials such as Fablon (Registered Trade Mark)formed of a single layer of thermoplastics material about 100 micronsthick having a decorated surface on one side are well known. Thesematerials suffer from the disadvantages that any imperfections in thesurface to which they are applied show through to the decorated side andfurthermore they tend to shrink by an excessive amount.

Decorative laminates comprising thermosetting plastic materials are alsoknown such as those sold under the name Formica (Registered Trade Mark)but these laminates are relatively more expensive and difficult to cutto size and apply to a surface.

It is an object of the present invention to provide a decorative sheetmaterial that may be applied to flat surfaces to obscure surfaceimperfections and present a decorated outer surface.

According to the present invention there is provided a decorativelaminate of thermoplastic material comprising a base layer and adecorative layer, the laminate having a total thickness in the range of250 to 450 microns and a shrinkage of less than 0.5% at ambienttemperatures and a rigidity in the lengthwise and crosswise directionsin the range of 25,000 to 30,000 Kilo Newtons per meter square. Having arigidity in this range ensures that surface imperfections aresatisfactorily obscured and also facilitates application of thelaminate.

The base layer can be two to four times the thickness of the decorativelayer and is preferably of rigid PVC containing only a small amount ofplasticizer, if any, i.e. up to 2% by weight, to minimize shrinkage ofthe laminate. The base layer can comprise entirely recycled material.

A protective layer can be provided on the decorative layer to minimizedamage to the decorative layer in use. The protective layer can be alacquer or a layer of clear film such as plasticized PVC which can havesubstantially the same thickness as the decorative layer. Alternativelya U.V. curable coating applied at between 5 and 50 grams per metersquare, e.g. of polyurethane or polyester, can provide improved marresistance, scratch resistance and stain resistance as compared to aplasticized PVC film.

The base layer, the decorative layer and the protective layer can eachbe PVC thermoplastic material but other thermoplastic materials can beused for some of the several layers.

An adhesive layer can be provided on the base layer to facilitate theapplication of the laminate. The adhesive layer is preferably a pressuresensitive adhesive covered by a release paper which can be readilyremoved prior to applying the laminate to the surface to be covered.

Examples of laminates according to the present invention will now bedescribed with reference to the FIGURE in the drawing.

EXAMPLE 1

The laminate comprises a base layer 1, of recycled rigid PVC 250 micronsthick and not containing plasticizer. A decorative layer 2 of PVC isprovided on one side of the base layer. The decorative layer is 90microns thick and printed with a pattern. To achieve a constant colorthe decorative layer is primarily of virgin material and can containnormal amounts of plasticizer to facilitate processing. Above thedecorative layer is a protective layer 3 of clear plasticizer PVC film80 microns thick. The total thickness of the laminate is 420 microns.

On the other side of the base layer 1 is a pressure sensitive adhesive 4covered by a release paper 5 which can be removed from the adhesivebefore applying the laminate to a surface to be covered.

The rigidity of the laminate in the lengthwise and crosswise directionswas 27,000 and 26,000 Kilo Newtons per meter square respectively and theshrinkage of the unapplied laminate over an extended period at ambienttemperature was 0.3%.

After removing the release paper a single sheet of the laminate wasreadily applied to a surface measuring 150 cm×60 cm without wrinkling orcreasing and without air being trapped between the surface and thelaminate. Surface imperfections of up to 350 microns both above andbelow the plane of the surface were not visible through the appliedlaminate.

The rigidity, combined with a choice of adhesive which develops its fulladhesive effect some time after the application of the laminate to thesurface, enabled the laminate to be removed and replaced to correcterrors in positioning the laminate on the surface.

When the laminate was applied to a melamine surface no shrinkage couldbe detected in the decorative material after a period of twelve monthsat ambient conditions.

EXAMPLE 2

The laminate comprises a base layer 1, of rigid PVC 320 microns thickand does not contain any plasticizer. A decorative layer 2 ofplasticizer PVC 90 microns thick and printed with a pattern is providedon one side of the base layer. Above the decorative layer is aprotective layer formed by a coating applied by roller coating as amixture of an acrylated polyurethane oligomer and an acrylate monomerand containing an organic photo-initiator. The coating was applied at 10grams per meter square. The coating was cured by ultra-violet radiationby passing beneath mercury vapour lamps with a power output of 300 wattsper linear inch at a speed of 10 to 15 meters per minute per lamp.

The total thickness of the laminate was 420 microns. On the other sideof the base layer a pressure sensitive adhesive 4 was provided togetherwith a release paper 5 as in Example 1.

The rigidity of the laminate in the lengthwise and crosswise directionswas 30,000 and 28,500 Kilo Newtons per meter square respectively and theshrinkage of the unapplied laminate over an extended period at ambienttemperature was 0.25%.

After removing the release paper the laminate was applied as inExample 1. As in Example 1 the laminate could be removed and reappliedand had the ability to obscure surface imperfections of up to 350microns both above and below the plane of the surface.

We claim:
 1. A decorative laminate comprising a protective layer, acontinuous decorative layer of polyvinyl chloride and a base layer ofrigid polyvinyl chloride containing not more than 2% plasticizer andhaving a thickness between 2 and 4 times the thickness of the decorativelayer, the laminate having a total thickness in the range of 250 to 450microns, a shrinkage of less than 0.5% at ambient temperatures, and arigidity in the lengthwise and crosswise directions in the range of25,000 to 30,000 Kilo Newtons per meter square.
 2. A laminate accordingto claim 1 wherein the base layer comprises recycled material.